#include <bits/stdc++.h>
using namespace std;

class Solution {
public:
    int maxProfit(vector<int>& prices) {
        if(prices.size()<2) return 0;
        else if(prices.size()==2) return max(0, prices[1]-prices[0]);
        
        int ans = 0;
        for(int i=1; i<prices.size(); ++i){
            if(prices[i]>prices[i-1]) ans+=prices[i]-prices[i-1];
        }
        return ans;
    }
};